DCGAN-Keras | Simple DCGAN implemented in Keras | Machine Learning library

I am trying to figure out how I will use the label information of my dataset with Generative Adversarial Networks. I am trying to use the following implementation of conditional GANs that can be found here. My dataset contains two different image domains (real objects and sketches) with common class information (chair, tree, orange etc). I opted for this implementation which only considers the two different domains as different "classes" for the correspondence (train samples X correspond to the real images while target samples y correspond to the sketch images).

Is there a way to modify my code and take into account the class information (chair, tree, etc.) in my whole architecture? I want actually my discriminator to predict whether or not my generated images from the generator belong to a specific class and not only whether they are real or not. As it is, with the current architecture, the system learns to create similar sketches in all cases.

Update: The discriminator returns a tensor of size 1x7x7 then both y_true and y_pred are passed through a flatten layer before calculating the loss:

This a part of the code for a Deconvolutional-Convoltional Generative Adversarial Network (DC-GAN)